Unable to browse internet

I have Compaq 1200 series notebook for the past week I have been unable to browse the internet or retreive my email. I have Winodows XP pro loaded. I can ping some site but not others (ie can ping ‘www.yahoo.com’, ‘www.dogpile.com’ but not ‘www.msn.com’.)

I have this problem using the built-in PPOE adapter as well as the dial-up adapter.

Has anyone come across this problem before?

Thank you in advance.